Ball bearings are a vital part of RC cars. Most of us abuse them day after day with little to no maintenance, and they keep on allowing our wheels to spin freely. Have you ever noticed your car pulling to one direction but your steering trim and toe are set perfectly straight? The culprit may be a seized bearing.
You will find sealed ball bearings of many different sizes throughout your car. They allow the axles to spin freely, steering to move left and right, differentials rotate and our engines spin to absurd rpms without failure. You most likely haven’t done so already, so now is the time to pay back these little unsung heroes with some maintenance.
STEP 1 – Break out the wrenches
You might be tempted to clean and oil your bearings on the car. Don’t bother. Though this is better than nothing, it’s best to remove the bearings to properly clean them. Bearings in hub carriers can sometimes be troublesome to remove. I like to use the axle, insert it partially, and wiggle it back and forth. The bearing will usually work itself free. If this method doesn’t work for you, remove the axle completely and try to punch the bearing out from the inside with a hex wrench or screwdriver. Be very careful when doing this. You don’t want to hit the seal of the bearing. Aim for the inner or outer bearing rings. Punching a dent in the seal can permanently damage the bearing.
TIP: Never use a water-based cleaner on your bearings. This can cause them to rust, which will lead to premature wear or failure.
STEP 2 – Inspect and Clean
Now that your bearings are out, give them a quick shot of motor spray and wipe with a rag to clean up the exterior. Visually inspect the bearings and look for obvious damage like dented or missing seals. If everything looks good, it’s time to thoroughly clean them. If the seals are dented or damaged in any way, replace the bearing.
TIP: Acetone is cheap and can be found at any hardware store. It works great for cleaning metal-shielded bearings, removing old tires off rims and cleaning the beads of new tires before mounting.
Rubber Sealed Bearings
The colored seals of these bearings can be removed and replaced. I like to use a hobby knife, wedge it from the inside of the seal, pop it up a bit and work my way around the bearing. Make sure not to use the sharp side of the knife and cut the seal. Go slowly and the seal should come off unscathed.
With the inner components exposed, this makes them very easy to clean. Spray the bearing out thoroughly with motor spray and then spin it with your fingers, feeling for roughness. If it feels dirty and rough still, repeat the dousing with motor spray. Once clean, the bearing should spin freely but will be a bit loud due to lack of lubricant.
Metal-shielded bearings are a bit harder to clean. A shot of motor spray does not always do the trick and the shields are not replaceable. Don’t worry, a little patience and some solvent will get the job done easily. I like to put all of my metal-shielded bearings in a small sealed bottle or plastic container mixed with some acetone or other solvent. Put on a lid and shake vigorously. Repeat this a few times. If the solvent gets very dirty, replace it with some fresh cleaner and repeat. You can speed up the process by using an RPM Bearing Blaster.
STEP 3 – Lubrication
The easiest and most important step to maintaining your bearings is oiling them. I don’t recommend using grease for RC bearings as dirt likes to stick to it very easily. However, almost any thin bearing oil from your local hardware store or hobby shop will do just fine.
TIP: Applying bearing oil with a small applicator tube makes it easy to keep the oil in your bearings and not on your bench.
For the rubber sealed bearings, simply add a few drops directly to the inners, put the seal back in place and lightly push down with your finger. It should snap right back into place with minimal effort.
I like to be able to spin metal-shielded bearings while oiling them. When spinning, the oil seems to seep past the shield a bit faster than just letting them sit.
Once your bearings are oiled they should quiet down again and spin freely. If your bearings are still gritty or slow after thoroughly cleaning and oiling them, it might be time to head down to your local hobby shop and replace them.
Maintaining your bearings often will lead to longer life out of the bearings and better performance from your car. If you don’t already, now is a great time to add it to your cleaning routine of your vehicle.
Words Brent Fiege | Photos John Cary